Apparatus for inflating tubeless tires

ABSTRACT

A tubeless tire inflating apparatus comprising an open-top cylindrical chamber having a radial air-sealing flange around its top edge that engages the bottom side wall of a tire, and a piston slidable within said chamber and having a sealing ring that engages the bottom flange of the wheel. Fixed to the underside of the piston at its center and projecting downwardly through a sealing ring in the bottom of the chamber is a tubular sleeve. A cylindrical shaft extends upwardly through the sleeve and through an aperture in the piston, and its bottom end is attached to the actuating rod of an air cylinder. A plate is detachably secured to the top end of the shaft and bears against the top side of the wheel, so that downward movement of the actuating rod causes the wheel and piston to be pulled downwardly, thereby sealing the top bead of the tire against the wheel. Air introduced into the tire through the rim valve fills the tire and leaks past the piston into the chamber, causing the piston to rise until the bottom bead of the tire seats against its flange.

United States Patet [1' 1 Matysak 51 Nov. 27, 1973 APPARATUS FORINFLATING TUBELESS TIRES [57 ABSTRACT A tubeless tire inflatingapparatus comprising an open- [76] Inventor: Edward A. Matysak, 612Greengate p cylindrical a b h g a radial air-Sealing St Cor n C lif,91720 flange around its top edge that engages the bottom side wall of atire, and a piston slidable within said [22] Flled: 1971 chamber andhaving a sealing ring that engages the [21] Appl. No.: 203,152 bottomflange of the wheel. Fixed to the underside of the piston at its centerand projecting downwardiy through a sealing ring in the bottom of thechamber is [52] US. Cl. 157/11 a tubular Sleeve. A cylindrical shaftextends upwardly CL ug t le e a d through a ap u e n t p s [58] Field ofSearch l57/1.1 ton and its bottom end is attached to the actuating i rodof an air cylinder. A plate is detachably secured to [56] References Cted the top end of the shaft and bears against the top side UNITEDSTATES PATENTS of the wheel, so that downward movement of the actu-2,936,827 5/1960 Riggs 157/l.l ating rod causes the wheel and piston tobe pulled 3,528,474 9/1970 May l57/Ll downwardly, thereby sealing thetop bead of the tire 3,016,934 Smyser against the wheeL Ai introducedinto the tire through 3,669,175 6/1972 SOIenSOn et al. l57/l.l the rimvalve fills the tire and leaks past he piston into the chamber, causingthe piston to rise until the j't' 15 223 Custer bottom bead of the tireseats against its flange.

tomeyer er 3 (Ilaims, 6 Drawing Figures 54 Q 5; J6 Z4 T B av 76 g i g If14 a 1 v 1a 73 i i l 3.112,; a a *"7 z 4 Z 1 it M g L Y t:

APPARATUS FOR INFLATING TUBELESS TIRES BACKGROUND OF THE INVENTION Thepresent invention pertains to apparatus for inflating a tubeless tiremounted on a drop-center rim.

The initial inflation of a tubeless tire mounted on a drop-center rimhas presented the industry with a serious problem in that, until thepresent invention, no completely satisfactory means has been found toestablish the initial contact of both tire beads with their respectiverim flanges. Until both tire beads are seated on their flanges, it isimpossible to inflate the tire, as air entering the tire through thevalve stem escapes through the gaps where sealing contact is not made.The problem is that the sidewalls of the uninflated tire normallycollapse toward each other in axial direction when initially mounted onthe wheel, and it is necessary to spread the beads apart axially so asto cause them to contact the axially spaced flanges.

Various attempts have been made to provide devices for squeezing thetread of the tire along its outer circumference, or otherwise causingthe tire beads to bulge outwardly into sealing contact with the wheelflanges until an initial sealing inflation could be effected, but thesehave all had various shortcomings that made them unsatisfactory. Amongthese have been various devices utilizing a chamber which cooperateswith the wheel flange and one side wall of the tire to form an air-tightenclosure, of which the tire is a part. When air is introduced into thisenclosure, the tire is inflated sufficiently to expand both beadsagainst their respective rim flanges in sealing contact therewith, afterwhich the tire can be inflated to its normal pressure in the usualmanner. However, such devices have had two serious shortcomings thathave prevented them from achieving commercial success: (1) they requiremanual effort to push the Wheel downwardly with respect to the tire soas to cause the top bead of the tire to engage the top flange of thewheel; and (2) there has never been a device of the class describedknown to applicant, in which there was not a serious air-leakage problemin the chamber, which resulted in the loss of so much air that there wasdifficulty in'keeping the pressure up. I

SUMMARY OF THE INVENTION The primary object of the present invention isto provide an improved apparatus for inflating tubeless tires which isconvenient and easy to use, and extremely economical of the compressedair that it uses. One feature of the invention is that it is designed tobe almost completely air-tight, and therefore wastes little or nocompressed air.

Another object of the invention is to provide apparatus of the classdescribed in which the wheel is pulled downwardly with respect to thetire by power actuated means, so as to effect sealing contact betweenthe upper tire bead and its wheel flange, and the only manual operationrequired of the operator is loading the tire and wheel on the apparatus,and removing it therefrom after inflation has been completed.

Still another object of the invention is to provide an apparatus forinflating tubeless tires which is simple and inexpensive to manufacture,ruggedly built for long, trouble-free service life, compact, andrequiring relatively low-pressure air to operate the device.

These objects are achieved by providing an open-top cylindrical chamberhaving a radial sealing flange around its upper edge which engages thebottom sidewall of a tire resting on the apparatus. Slidable verticallywithin the chamber is a piston having an annular sealing ring on its topsurface that engages the bottom rim flange of the wheel. A cylindricalsleeve is fixed to the underside of the piston at its center, and thesleeve passes downwardly through an annular seal in the bottom of thechamber. A cylindrical shaft is attached at its bottom end to theactuating rod of an air cylinder, and passes upwardly through the sleeveand an aperture in the piston, and through the center of the wheel. Aplate is detachably secured to the top end of the shaft and bearsagainst the top surface of the wheel. Thus, when the air cylinder isenergized, the actuating rod is retracted downwardly, pulling the wheeldown with it and causing the top bead of the tire to contact the wheelrim in an air-sealing engagement. With the interior of the tire thussealed on the top side by engagement of the upper bead with the upperwheel flange, and on the bottom side by the air chamber which is boundedon one edge by the contact line of the lower rim flange with the annularsealing ring on the piston, and on the other edge by the contact line ofthe lower tire sidewall with the radial sealing flange on the chamber,the tire can be inflated in the usual manner until both beads are seatedagainst their rim flanges, and thereafter brought up to normal pressure.Air leakage from the chamber is prevented by the cylindrical sleeve onthe underside of the piston which passes through the annular seal in thebottom of the chamber, and the downward pull on the wheel, which isnecessary to effect sealing contact of the upper tire bead with theupper wheel flange, is accomplished by the cylindrical shaft that passesthrough the center of the sleeve, and which is attached at its bottomend to the actuating rod of the air cylinder.

The foregoing and other objects and advantages of the invention willbecome apparent to those skilled in the from the following detaileddescription of the preferred embodiment, with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of atubeless tire inflating apparatus embodying the principles of theinvention;

FIG. 2 is an enlarged vertical section of the same, showing a tire andwheel positioned on the apparatus with the wheel pulled downwardly bythe air cylinder in the base of the machine;

FIG. 3 is another view similar to FIG. 2, but showing the tire inflatedto the stage where both beads are seated on their respective rimflanges;

FIG. 4 is a further enlarged, fragmentary sectional view, showing theplate detachably mounted on the top end of the cylindrical shaft, andthe manner in which the plate bears against the top surface of thewheel;

FIG. 5 is an enlarged, fragmentary sectional view taken through theannular seal in the bottom of the chamber, through which the cylindricalsleeve passes; and

FIG. 6 is an enlarged axial section through the air cylinder and piston,which are located in the base of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the apparatusof the present invention is designated in its entirety by the referencenumeral l0, and comprises a generally rectangular, boxlike base 12, uponwhich a cylindrical chamber 14 is mounted. The chamber 14 is disposedwith its axis extending vertically, and the bottom of the chambercomprises a circular plate 16 which is welded around the edges to thecylindrical sidewalls 18. Projecting radially outward and inclineddownwardly at a slight angle from the top edge of sidewall 18 is anannular flange 20 having an upturned lip 21 around its outer edge, andcemented to the top of the flange is a ring 22 of elastomeric material,preferably sponge rubber or polyurethane foam, which serves to form anairtight seal with the sidewall of a tire 24 when the latter is restingon the ring, as shown in FIGS. 2 and 3.

Slidable vertically within the cylindrical chamber 14 is a relativelyshallow piston 26 formed of steel plate and having a downwardly turnedannular flange 28 on ts Out r q iiahsrxi whi h i idqahls thin t walls ofthe chamber 14, but with ample clearance so that air can leak down pastthis flange without any difficulty, to fill the chamber. The outerportion 30 of the piston 26 is sloped conically to the same angle as theflange 20 on the chamber 14, and cemented to the top surface of thisconically sloped portion is a ring 32 of sponge rubber or polyurethanefoam, which makes an airtight seal with the bottom flange 34 of thewheel rim 36, upon which tire 24 is mounted.

Welded to the underside of the piston 26 at the center thereof is adownwardly extending cylindrical sleeve 38, which projects down througha hole in the center of the chamber bottom 16 into the space enclosed bythe base 12. Sleeve 38 also passes through the opening of an annularsteel plate 40 which is supported around its outer edge on a ring 42,and the latter is supported, in turn, on the chamber bottom 16. Plate 40and ring 42 form an annular housing which surrounds and encloses asealing ring 44 that slidably engages the outer surface of sleeve 38. Alimit stop ring 46 is bolted to the bottom end of sleeve 38 and engagesthe underside of chamber bottom 16 when the piston 26 is at the upperlimit of its travel, as shown in FIG. 3. Surrounding the sleeve 38 is ahelical compression spring 48, the bottom end of which bears againstplate 40, and the top end bears against the underside of piston 26.Spring 48 urges the piston 26 upwardly to the position shown in FIG. 3,and yields to allow the piston to move downwardly within the chamber, asin FIG. 2.

Slidable vertically within a hole in the center of piston 26 is acylindrical tube 50. Tube 50 extends downwardly through the center ofsleeve 38 and at its bottom end is secured by a pin 52 at the top end ofthe piston rod 54 of an air cylinder 56. Tube 50 thus serves as anextension for piston rod 54, and the two move as one. Surrounding thetube is a helical compression spring 57, the top end of which extends upinto sleeve 38 and abuts against the underside of the piston 26. Thebottom end of spring 57 bears against pin 52 and exerts a downwardthrust against the piston rod and extension 54, 50, tending to push thesame downwardly with respect to the piston 26. At the same time, anequal upward thrust is exerted by spring 57 against piston 26,augmenting the upward thrust of spring 48.

Air cylinder 56 is of the double-acting type, and has a piston 58 (FIG.6) with two axially-spaced, annular grooves, in which oppositely facingsealing rings 60 and 61 are seated. Top ring 60 prevents air fromescaping downwardly past the piston, while bottom ring 61 prevents theescape of air upwardly. Piston rod 54 also passes through a sealing ring62 in the top end 63 of the cylinder, which prevents the escape of airthrough the clearance between rod 54 and the cylinder top. Air underpressure is supplied to the top end of the cylinder through a flexibleair line 64, which is connected to the cylinder by a fitting 65. Thebottom end of the cylinder is supplied with air under pressure by aflexible air line 66, which is connected to the cylinder by a fitting67. The two air lines 64 and 66 go to a control valve housing 68 mountedon a bracket 70 on the outside of chamber 14. Valve housing 68 issupplied with pressurized air by an air supply line 72, which isconnected to a source of high-pressure air. Line 72 is connected to onebranch of a T-fitting 73 projecting from the side of housing 68, andanother air hose 74 is connected to the other branch. Hose 74 has theusual air chuck (not shown) on its other end, by means of which the tire24 is inflated through valve 75 on the wheel rim 36.

The valve mechanism in housing 68 is actuated by a spring-loaded controlbutton 76 from the front side of the housing. In the normal, extendedposition of the control button 76, the valve sends air pressure throughhose 64 to the top end of the air cylinder 56, causing the piston rod 54to be retracted. Welded to the top end of the tube 50 is a circular disk80 of somewhat larger diameter than the outside diameter of the tube, sothat the outer edge of the disk projects radially beyond the tube. Thetube 50 extends upwardly through the central opening 81 in the wheel 82,and inserted between the overhanging lip of disk 80 and the top surfaceof the wheel 82 is a keeper plate 83. Keeper plate 83 has a pad 84 ofsoft rubber cemented to its underside, and the pad rests on the lug boltbosses of the wheel, as best seen in FIG. 4. The keeper plate 83 has awedge-shaped opening 85 cut into one side thereof and extending all theway in to the center of the plate, where the width of the opening issubstantially the same as the outside diameter of the tube. 50. The disk80 thus overhangs the keeper plate 83 and bears against the top surfaceof the same, so that when the piston rod 54 is pulled downwardly by theair cylinder 56, the wheel 82 is pulled downwardly with it by the keeperplate 83. Plate 83 can be inserted between the disk 80 and wheel 82 bysliding it horizontally, with the opening 85 positioned to receive thetube 50. In order to insert the plate between the disk 80 and wheel 82,it is necessary to extend the piston rod 54 by pressing inwardly on thecontrol button 76, which causes the valve to send air pressure throughline 66to the bottom end of the cylinder 56, while the top end is ventedto the atmosphere. Air pressure in the bottom end of the cylinder forcespiston 58 upwardly, raising the tube 50 so that disk 80 clears the topof the wheel. Plate 83 has a handle 86 fixed to its top side near theedge opposite the opening 85, which facilitates handling of the plate.

In addition to its function of pulling the wheel 82 downwardly when airpressure is admitted to the top end of cylinder 56, the keeper plate 83and air cylinder also provide a safety feature by virtue of the positiverestraint exerted on the wheel during the inflation process, in theevent that the air pressure suddenly becomes too great. In certain priortire inflaters, it is possible for the wheel rim to blow out of the tirewith great force, and there have been a number of fatal accidents ofthis kind. Such accidents are impossible with the present invention, asthe wheel is positively held by the keeper plate 83 against beinghurdled upwardly by the piston 26.

The operation of the invention is as follows: With the keeper plate 83removed from under the disk 80, an uninflated tire 24 mounted on a wheel82 is placed on top of the apparatus 10, with the bottom sidewall of thetire resting on the outer sealing ring 22 of the chamber 14, and thebottom rim flange 34 of the wheel resting on the inner sealing ring 32of the piston 26. Valve control button 76 is pressed inwardly, causingtube 50 to rise through the central aperture of the wheel, until thedisk 80 is well above the lug bolt bosses of the wheel. Keeper plate 83is theninserted under the disk 80. When button 76 is released, airpressure is admitted to the top of cylinder 56, causing the tube 50 tobe pulled downwardly, and the wheel 82 with it. As the piston reachesthe bottom of its stroke, the relative positions of the several partsare as shown in FIG. 2. It will be noted that the bottom sidewall of thetire is pressed tightly against sealing ring 22; and bottom rim flange34 is pressed tightly against sealing ring 32. The downward pull onwheel 82 by tube 50 has the effect of pushing the tire upwardly withrespect to the wheel, and the upper bead 90 of the tire is thereforeforced up onto the upper portion of the wheel rim, as shown in FIG. 2.This contact of upper bead 90 against the wheel rim provides an air sealat this point, thereby forming an airtight enclosure which includes theinside of the tire and the inside of chamber 14 below the piston 26. Asmentioned earlier, the downwardly turned flange 28 has sufficientclearance between it and the chamber sidewall 18, so that air can leakaround the flange into the chamber 14 as fast as it is supplied to thetire. The sliding sleeve 38 is sealed by ring seal 44 where it passesthrough the bottom 16 of the chamber. Thus, when air is introduced intothe tube through the valve 75 using the air chuck on the end of hose 74,the pressure builds up, both within the tire and within chamber 14, dueto leakage of air past flange 28. As the tire becomes partiallyinflated, the pressure of the air against the side walls causes the topbead of the tire to force itself up against the upper rim flange 34';and at the same time, air pressure acting against the underside ofpiston 26 causes the latter to be forced upwardly against the resistanceof the air cylinder 56, until the piston reaches the top of its stroke.At this point, the position of the several parts of the apparatus is asshown in FIG. 3. With both beads now tightly sealed against theirrespective rim flanges, the tire is airtight, and inflation can becontinued until the desired pressure is reached. To remove the tire,valve control button 76 is depressed, raising the tube 50 so as torelease pressure of the disk 80 against keeper plate 83, and the latteris removed. The tire and wheel can then be removed from the apparatus.

While I have shown and described in considerable detail what I believeto be the preferred form of my invention, it will be understood by thoseskilled in the art that various changes may be made without departingfrom the broad scope of the following claims.

I claim:

1. Apparatus for inflating a tubeless tire mounted on a wheel having rimflanges against which the tire beads seat when inflated, said apparatuscomprising:

a cylindrical chamber mounted with its axis perpendicular to the ground,said chamber having a closed bottom, an open top, and radial flangesaround its top perimeter;

first sealing means on said flange engageable with the bottom sidewallof a tire resting on the apparatus so as to provide an airtight seal atthis point;

a piston slidable within said chamber;

second sealing means on the top surface of said piston adjacent theouter edge thereof, said second sealing means being engageable by thelower rim flange of said wheel to provide an airtight seal at thispoint;

a cylindrical sleeve fixed to the underside of said piston in anairtight junction therewith, passing downwardly through an opening inthe bottom of said chamber;

third sealing meanssurrounding said sleeve at the point where it passesthrough said opening, so as to provide an airtight seal at this point;

an air cylinder mounted below said chamber with its piston rodlongitudinal axis-coaxial with the axis of said chamber, said aircylinder having a piston, a piston rod, and an extension thereforpassing upwardly through said sleeve and through an aperture in saidfirst-named position, and through the central opening of said wheel;

a keeper detachably connected to the top end of said piston rodextension, said keeper bearing against the top of said wheel;

manually controllable valve means operable to admit high pressure air tothe bottom end of said air cylinder when the valve is actuated, so as toextend said piston rod and its extension;

said valve means normally admitting pressure air from a source to thetop end of said cylinder when the valve is not being manually actuated,so as to retract said piston rod and its extension, the downward pull ofsaid piston rod extension and keeper against said wheel causing saidagainst said first sealing means, and the lower rim flange of the wheelto press tightly against said second sealing means, and the upper tirebead to press tightly against the upper portion of the wheel rim; and

means for admitting pressure air from said source into the interior ofsaid tire and into said chamber below said second sealing means, saidair being confined by said first, second and third sealing means so thatthe pressure builds up rapidly;

bottom sidewall of V the tire to press tightly against the resistance ofthe air cylinder piston. 2. The apparatus of claim 1, which furtherincludes a compression spring surrounding said cylindricalsleeveandexerting an upyyard thrust against firstnamed piston, thebottom end of said spring being supported by the bottom of said chamber.

3. The apparatus of claim 2, which further includes against theunderside of said first piston, and the lower end thereof being attachedto said piston rod extension.

1. Apparatus for inflating a tubeless tire mounted on a wheel having rimflanges against which the tire beads seat when inflated, said apparatuscomprising: a cylindrical chamber mounted with its axis perpendicular tothe ground, said chamber having a closed bottom, an open top, and radialflanges around its top perimeter; first sealing means on said flangeengageable with the bottom sidewall of a tire resting on the apparatusso as to provide an airtight seal at this point; a piston slidablewithin said chamber; second sealing means on the top surface of saidpiston adjacent the outer edge thereof, said second sealing means beingengageable by the lower rim flange of said wheel to provide an airtightseal at this point; a cylindrical sleeve fixed to the underside of saidpiston in an airtight junction therewith, passing downwardly through anopening in the bottom of said chamber; third sealing means surroundingsaid sleeve at the point where it passes through said opening, so as toprovide an airtight seal at this point; an air cylinder mounted belowsaid chamber with its piston rod longitudinal axis coaxial with the axisof said chamber, said air cylinder having a piston, a piston rod, and anextension therefor passing upwardly through said sleeve and through Anaperture in said first-named position, and through the central openingof said wheel; a keeper detachably connected to the top end of saidpiston rod extension, said keeper bearing against the top of said wheel;manually controllable valve means operable to admit high pressure air tothe bottom end of said air cylinder when the valve is actuated, so as toextend said piston rod and its extension; said valve means normallyadmitting air to the top end of said cylinder when the valve is notbeing manually actuated, so as to retract said piston rod and itsextension, the downward pull of said piston rod extension and keeperagainst said wheel causing said bottom sidewall of the tire to presstightly against said first sealing means, and the lower rim flange ofthe wheel to press tightly against said second sealing means, and theupper tire bead to press tightly against the upper portion of the wheelrim; and means for admitting high pressure air into the interior of saidtire and into said chamber below said second sealing means, said airbeing confined by said sealing means so that the pressure builds uprapidly within the tire and chamber, the air pressure within saidchamber acting against the underside of said first-named piston to pushthe latter upwardly against the resistance of said air cylinder; thearea of said first-named piston being substantiallu greater than thearea of said air-cylinder piston, so that the total force exertedagainst said first-named piston is greater than the opposing forceexerted by the air-cylinder piston, causing said first piston to moveupwardly to its upper extreme position against the resistance of the aircylinder piston.
 2. The apparatus of claim 1, which further includes acompression spring surrounding said cylindrical sleeve and exerting anupward thrust against said first-named piston, the bottom end of saidspring being supported by the bottom of said chamber.
 3. The apparatusof claim 2, which further includes a second compression springsurrounding said piston rod extension and extending up into saidcylindrical sleeve, the upper end of said second spring bearing againstthe underside of said first piston, and the lower end thereof beingattached to said piston rod extension.